High explosive mixtures



United States Patent Ofiice p 3,111,439 HIGH EXPLGSIVE MIXTURES btephen Brunauer, 3417 Quebec St. NW., Washington, DC. No Drawing. Filed July 6, 1949, Ser. No. 103,321 2 Claims. (Cl. 149-92) (Granted under Title 35, US. Code (1952), see. 266) This invention relates to high explosive compositions and particularly to such compositions formed by mixing powdered metals with one or more explosive substances having a positive oxygen balance.

Attempts have heretofore been made to increase the power of high explosives by incorporating therein finely divided aluminum which serves to increase the amount of heat energy liberated during detonation. To achieve this result, aluminum has been combined with ammonium nitrate, mixtures of ammonium nitrate and alkali nitrates, mixtures of ammonium nitrate and trinitrotoluene and other types of explosive substances. Compositions such as Ammonal B, Ripping Animon al, St. Helens Powder and Gesteins-Westfalit B and C have resuited ifrom this admixture of powdered aluminum with explosive substances. Upon detonation, these aluminized explosives release energy in the form of heat of the order of 1.2 to 1.5 times the amount of energy released during the detonation of a similar quantity of trinitrotoluene. However, the known explosives of this type are incapable of producing the maximum release of energy since suificient quantities of aluminum are lacking and thus portions of the available oxygen are expended in lower energy producing reactions.

It is, therefore, an object of this invention to provide an improved high explosive composition which has a positive oxygen balance and which contains a sutficient quantity of readily oxidizable metallic substance having a heat of oxidation characteristic which insures not only complete reaction with all of the available oxygen but also the liberation of maximum energy in the form of heat.

Another object of this invention is the provision of improved high explosive compositions which upon detonation release heat energy of from 3 to 6.2 times the heat energy released upon the detonation of an equal weight of trinitrotolnene.

Military explosives are compounds or mixtures of .cOmpountls containing carbon, hydrogen, nitrogen and oxygen. The oxygen is initially attached to the nitrogen atoms and the explosion is a rapid chemical reaction in which the nitrogenoxygen bonds are broken. The oxygen unites with the hydrogen and carbon atoms, producing oxides of these elements, i.e., (water, carbon monoxide and carbon dioxide. The amount of heat energy created during this oxidizing action is dependent upon the heat of oxidation of the particular substance undergoing oxidation. In the case of the oxides of carhen, the heats of oxidation are Calories per gram or carbon Carbon to carbon monoxide 2200 Carbon to carbon dioxide 7800 The heat of oxidation of aluminum to aluminum oxide (Al O is 7,220 calories per gram. which is less than the heat of oxidation of carbon to carbon dioxide. Thus, while in an oxygen deficient explosive the addition of aluminum always results in an increase of the energy released in the explosion, in a Well balanced explosive the addition of aluminum may result in a decrease in the heat of explosion. Upon detonation of aluminized explosives as are described above, it is known that reaction products including carbon monoxide and water va- Lithium 10,2100 Beryllium 15,700 Boron 12,900

In order to obtain the release of maximum caloric energy upon detonation of my new explosives, it is necessary to employ one of these metals in the proper Iatomic proportion in the explosive mixture so that all of the oxygen of the carrier is utilized in the formation of the metallic oxide.

in order to obtain explosive substances of the character contemplated by this invention, explosive materials which have a positive oxygen balance are utilized with the above disclosed powdered metals. The following formula for oxygen balance may be employed in determining the oxygen containing explosives iwhich are suitable for use:

1 Oxygen balance= wherein z=nurnber of oxygen atoms x=nurnber of carbon atoms y=number of hydrogen atoms M=molecular weight of compound Example 1 Parts (by weight) Liquid ozone 63.9 Beryllium 36.1

The heat released in the explosion of the above explosive mixture is 6100 calories per gram of explosive. The heat released in the explosion of trinitrotoluene is 990 calories per :gram. Thus the explosive mixture of this example releases 6.2 times as much heat per gram as trinitrotoluene. The :density of the beryllium-ozone mixture is 1.76 while that of trinitrotoluene is 1.57 from which it is determined that the ratio of heat released on an equal volume basis is 6.8.

Example 2 Parts (by weight) Liquid oxygen 53.5 Lithium 46.5

The heat released in the explosion of the above explosive mixture is 4750- calories per gram which comprises 4.8 times the heat of explosion of trinitrotoluene on an equal weight basis. Owing to the low density of lithium, this explosive mixture has a low density of 0.745. Thus considered on an equal volume basis, the heat released by this explosive is only 2.3 times the heat released by the explosion of trinitrotoluene.

Example 3 Parts (by weight) Hydrogen peroxide 70.3 Boron During the explosion of this mixture, 2,920 calories per gram are released which is 3.0 times the heat of explosion of trinitrotoluene. The density of the hydrogen peroxide-boron mixture is 1.66 and the heat of explosion is 4,850 calories per cubic centimeter which is equivalent to 3.1 times the heat of explosition of trinitrotoluene determined on an equal volume basis.

Example 4 Parts (by weight) Tetranitromethane 73.1 Beryllium 26.9

The heat of explosion of the above explosive mixture is 4,080 calories per gram. The density of the explosive is 1.70. The ratio of the heat of explosition of this explosive to that of trinitrotoluene is 4.1 determined on an equal weight basis and 4.5 on an equal volume basis.

Example 5 Parts (by weight) Bis-trinitroethyl nitrarnine 75.5 Beryllium 24.5

The heat of explosion of the above explosive mixture is 3,870 calories per gram and the density of the explosive is 1.80. The ratio of the heat of explosion to that of trinitrotol-uene is 3.9 determined on an equal weight basis and 4.4 on an equal volume basis.

Example 6 Parts (by weight) Bis-trinitroethyl nitra-mine 64.8 Trinitrotoluene 11.4 Beryllium 23.8

The heat of explosion of the above explosive mixture is 3,750 calories per gram and it has a density of 1.77. The ratio of the heat of explosion to that of trinitrotoluene is 3.8 determined on an equal Weight basis and 4.2 on an equal volume basis.

The oxygen containing components of Examples 1 to 4 are employed in liquid form and those of Examples 5 and 6 exist in solid form at ambient temperatures. The lithium, beryllium and boron are preferably employed in the state of finely divided powders in order to present as .great a surface as possible to facilitate the instantaneous oxidation of the metal.

It is contemplated that additional substances may be incorporated in the explosive mixtures Without departing from the spirit of my invention. For example, the ex plosive mixtures of Examples 1 to 4 may be mixed with an inert carrier such as kieselguhr in order to obtain the explosive in a physical form which may be more readily used in certain applications. Further, the sensitivity of the explosive mixtures of Examples 5 and 6 may be reduced to prevent premature detonation by adding thereto 5 parts of a micro-crystalline wax such for example as beeswax, Stanolind wax or Aristo wax to 100 parts of the mixture.

The general rules under which explosives are safely handled will suffice to prevent undue hazard in the use of the above compositions. When the components of the explosive composition are solid, they may be freely mixed and detonated, as are other explosives, by the use of a primer or the like. When liquid oxidizers are used, the present compositions may safely be utilized by combining the liquid with the metal powder at the time the explosion is initiated. Such procedure is old and well known in the art. This is somewhat analogous to the procedure utilized in keeping two hypergolic liquids separated in rockets until the rocket is launched. In the case of liquid oxidizers the metal powders are wetted by the liquid and its consistency will be determined by the proportions and properties of liquid and solid used. rec degree of subdivision of the solid is not critical. Any degree of subdivision norm-ally regarded as powdered is suitable. If utilized as suggested above, the storage and handling of the material is accomplished by procedures already developed in the handling and storage of related explosives. Insofar as liquid ozone is concerned, it is well known that this liquid may be stabilized by removal of all contaminants. i

In the above discussion, explosive mixtures have been compared on the basis of the energy released in the detonation as a measure of explosive power and trinitrotoluene has been used as a comparative reference expiosive. It is realized that the heat of explosion is not a complete measure of the effectiveness of explosives for all of their applications. In certain applications, such as in confined space explosions, cratering, etc., the heat of explosion comes close to being a complete measure of explosive effectiveness. In other military applications, such as air blast, fragmentation, shaped charges, etc., the heat of explosion is not a complete measure of explosive effectiveness. However, in all applications the heat of explosion is a vitally important property of the explosive, indeed, probably the most important property of the explosive.

There are other properties which are important in comparing explosives. One such property is the density of the explosive. The importance of this property becomes obvious when explosives .are compared on an equal volume basis. Thus the explosive given in Example 2 is greatly superior to the explosive given in Example 3 on equal weight basis, but inferior on equal volume basis. The implication of this is that in a given weapon, the size of which is fixed, the hydrogen peroxide-boron mixture of Example 3 is superior to the liquid oxygen-lithium mixture of Example 2, but in some other application where weight is the decisive factor the latter is superior to the former.

Another important property of the explosive is the detonation pressure. In the detonation, the usually solid or liquid explosive is converted into gaseous and solid products (such as A1 0 BcO, CO, H O, etc.). In the first instant the resulting gases occupy the same volume as the original explosive minus the solid reaction products, consequently the pressure is tremendously high. The magnitude of the detonation pressure has a very important bearing on such properties of the explosive as detonation velocity, fragmentation effectiveness, shaped charge effectiveness, etc. If it is assumed that in the detonation process A1 0 and B 0 are obtained as solid products, then the detonation pressure of the boronized explosive will be much higher than that of the aluminized explosives, because of the much greater density of A1 0 Detailed calculations show that the detonation pressure of .a Torpex type of composition (RDX/ TNT/aluminum 42/40/18) is less than that of Composition B (RDX/TNT /40), whereas that of the boronized explosive (RDX/TNT/B 43/41/16) is much greater than that of Composition B. The figures compared to trinitrotoluene are: 1.2 for the detonation pressure of Composition B, 1.0 for Torpex and 2.6 for the boronized explosive. Actually, the detonation velocity, the fragmentation effectiveness and shaped charge effectiveness of Composition B is greater than that of Torpex and on the basis of calculations, boronized RDX/TNT is much more effective than Composition B.

From the above discussion it will be apparent that my improved high explosive compositions contain an explosive with positive oxygen balance and contain sufficient amounts of readily oxidizable substances selected from lithium, beryllium and boron to react with all of the oxygen present in order to produce maximum caloric energy upon detonation.

Obviously many modifications and variations of the explosive mixtures are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

What is claimed is:

1. An explosive composition of matter comprising a mixture of 64.8 parts by weight of bis-trinitroethyl nitramine, 11.4 parts by weight of trinitrotoluene and 23.8 parts by Weight of powdered beryllium, said composition having a heat of explosion of 3,750 calories per gram and a density of 1.77.

2. An explosive composition of matter comprising a mixture of 648 parts by weight of bis-trinitroethyl nitramine, 11.4 parts by Weight of trinitrotoluene, 23.8

parts by weight of powdered beryllium and a microcrys-talline wax in an amount equal to about 5 percent of the combined Weight of the remaining constituents.

References Cited in the file of this patent UNITED STATES PATENTS 1,506,323 ONeill Aug. 26, 1924 2,461,797 Zwicky Feb. 15, 1949 FOREIGN PATENTS 199,734 Great Britain Dec. 20, 1923 320,464 France Dec. 11, 1902 OTHER REFERENCES 

2. AN EXPLOSIVE COMPOSITION OF MATTER COMPRISING A MIXTURE OF 64.8 PARTS BY WEIGHT OF BIS-TRINITROETHYL NITRAMINE, 11.4 PARTS BY WEIGHT OF TTRINITROTOLUENE, 23.8 PARTS BY WEIGHT OF POWDERED BERYLLIUM AND A MICROCRYSTALLINE WAX IN AN AMOUNT EQUAL TO ABOUT 5 PERCENT OF THE COMBINED WEIGHT OF THE REMAINING CONSTITUENTS. 